1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* 18 * Miscellaneous utility functions. 19 */ 20 #ifndef _DALVIK_MISC 21 #define _DALVIK_MISC 22 23 #include "Inlines.h" 24 25 #include <stdio.h> 26 #include <sys/types.h> 27 #include <sys/time.h> 28 29 /* 30 * Used to shut up the compiler when a parameter isn't used. 31 */ 32 #define UNUSED_PARAMETER(p) (void)(p) 33 34 /* 35 * Floating point conversion functions. These are necessary to avoid 36 * strict-aliasing problems ("dereferencing type-punned pointer will break 37 * strict-aliasing rules"). According to the gcc info page, this usage 38 * is allowed, even with "-fstrict-aliasing". 39 * 40 * The code generated by gcc-4.1.1 appears to be much better than a 41 * type cast dereference ("int foo = *(int*)&myfloat") when the conversion 42 * function is inlined. It also allows us to take advantage of the 43 * optimizations that strict aliasing rules allow. 44 */ 45 INLINE float dvmU4ToFloat(u4 val) { 46 union { u4 in; float out; } conv; 47 conv.in = val; 48 return conv.out; 49 } 50 INLINE u4 dvmFloatToU4(float val) { 51 union { float in; u4 out; } conv; 52 conv.in = val; 53 return conv.out; 54 } 55 56 /* 57 * Print a hex dump to the log file. 58 * 59 * "local" mode prints a hex dump starting from offset 0 (roughly equivalent 60 * to "xxd -g1"). 61 * 62 * "mem" mode shows the actual memory address, and will offset the start 63 * so that the low nibble of the address is always zero. 64 * 65 * If "tag" is NULL the default tag ("dalvikvm") will be used. 66 */ 67 typedef enum { kHexDumpLocal, kHexDumpMem } HexDumpMode; 68 void dvmPrintHexDumpEx(int priority, const char* tag, const void* vaddr, 69 size_t length, HexDumpMode mode); 70 71 /* 72 * Print a hex dump, at INFO level. 73 */ 74 INLINE void dvmPrintHexDump(const void* vaddr, size_t length) { 75 dvmPrintHexDumpEx(ANDROID_LOG_INFO, LOG_TAG, 76 vaddr, length, kHexDumpLocal); 77 } 78 79 /* 80 * Print a hex dump at VERBOSE level. This does nothing in non-debug builds. 81 */ 82 INLINE void dvmPrintHexDumpDbg(const void* vaddr, size_t length,const char* tag) 83 { 84 #if !LOG_NDEBUG 85 dvmPrintHexDumpEx(ANDROID_LOG_VERBOSE, (tag != NULL) ? tag : LOG_TAG, 86 vaddr, length, kHexDumpLocal); 87 #endif 88 } 89 90 /* 91 * We pass one of these around when we want code to be able to write debug 92 * info to either the log or to a file (or stdout/stderr). 93 */ 94 typedef struct DebugOutputTarget { 95 /* where to? */ 96 enum { 97 kDebugTargetUnknown = 0, 98 kDebugTargetLog, 99 kDebugTargetFile, 100 } which; 101 102 /* additional bits */ 103 union { 104 struct { 105 int priority; 106 const char* tag; 107 } log; 108 struct { 109 FILE* fp; 110 } file; 111 } data; 112 } DebugOutputTarget; 113 114 /* 115 * Fill in a DebugOutputTarget struct. 116 */ 117 void dvmCreateLogOutputTarget(DebugOutputTarget* target, int priority, 118 const char* tag); 119 void dvmCreateFileOutputTarget(DebugOutputTarget* target, FILE* fp); 120 121 /* 122 * Print a debug message. 123 */ 124 void dvmPrintDebugMessage(const DebugOutputTarget* target, const char* format, 125 ...) 126 #if defined(__GNUC__) 127 __attribute__ ((format(printf, 2, 3))) 128 #endif 129 ; 130 131 132 /* 133 * Expanding bitmap, used for tracking resources. Bits are numbered starting 134 * from zero. 135 * 136 * All operations on a BitVector are unsynchronized. 137 */ 138 typedef struct BitVector { 139 bool expandable; /* expand bitmap if we run out? */ 140 int storageSize; /* current size, in 32-bit words */ 141 u4* storage; 142 } BitVector; 143 144 /* allocate a bit vector with enough space to hold "startBits" bits */ 145 BitVector* dvmAllocBitVector(int startBits, bool expandable); 146 void dvmFreeBitVector(BitVector* pBits); 147 148 /* 149 * dvmAllocBit always allocates the first possible bit. If we run out of 150 * space in the bitmap, and it's not marked expandable, dvmAllocBit 151 * returns -1. 152 * 153 * dvmSetBit sets the specified bit, expanding the vector if necessary 154 * (and possible). 155 * 156 * dvmIsBitSet returns "true" if the bit is set. 157 */ 158 int dvmAllocBit(BitVector* pBits); 159 bool dvmSetBit(BitVector* pBits, int num); 160 void dvmClearBit(BitVector* pBits, int num); 161 void dvmClearAllBits(BitVector* pBits); 162 bool dvmIsBitSet(const BitVector* pBits, int num); 163 164 /* count the number of bits that have been set */ 165 int dvmCountSetBits(const BitVector* pBits); 166 167 /* copy one vector to the other compatible one */ 168 bool dvmCopyBitVector(BitVector *dest, const BitVector *src); 169 170 /* 171 * Intersect two bit vectores and merge the result on top of the pre-existing 172 * value in the dest vector. 173 */ 174 bool dvmIntersectBitVectors(BitVector *dest, const BitVector *src1, 175 const BitVector *src2); 176 177 #define kBitVectorGrowth 4 /* increase by 4 u4s when limit hit */ 178 179 180 /* 181 * Return a newly-allocated string in which all occurrences of '.' have 182 * been changed to '/'. If we find a '/' in the original string, NULL 183 * is returned to avoid ambiguity. 184 */ 185 char* dvmDotToSlash(const char* str); 186 187 /* 188 * Return a newly-allocated string for the "dot version" of the class 189 * name for the given type descriptor. That is, The initial "L" and 190 * final ";" (if any) have been removed and all occurrences of '/' 191 * have been changed to '.'. 192 */ 193 char* dvmDescriptorToDot(const char* str); 194 195 /* 196 * Return a newly-allocated string for the type descriptor 197 * corresponding to the "dot version" of the given class name. That 198 * is, non-array names are surrounde by "L" and ";", and all 199 * occurrences of '.' have been changed to '/'. 200 */ 201 char* dvmDotToDescriptor(const char* str); 202 203 /* 204 * Return a newly-allocated string for the internal-form class name for 205 * the given type descriptor. That is, the initial "L" and final ";" (if 206 * any) have been removed. 207 */ 208 char* dvmDescriptorToName(const char* str); 209 210 /* 211 * Return a newly-allocated string for the type descriptor for the given 212 * internal-form class name. That is, a non-array class name will get 213 * surrounded by "L" and ";", while array names are left as-is. 214 */ 215 char* dvmNameToDescriptor(const char* str); 216 217 /* 218 * Get the current time, in nanoseconds. This is "relative" time, meaning 219 * it could be wall-clock time or a monotonic counter, and is only suitable 220 * for computing time deltas. 221 */ 222 u8 dvmGetRelativeTimeNsec(void); 223 224 /* 225 * Get the current time, in microseconds. This is "relative" time, meaning 226 * it could be wall-clock time or a monotonic counter, and is only suitable 227 * for computing time deltas. 228 */ 229 INLINE u8 dvmGetRelativeTimeUsec(void) { 230 return dvmGetRelativeTimeNsec() / 1000; 231 } 232 233 /* 234 * Get the current time, in milliseconds. This is "relative" time, 235 * meaning it could be wall-clock time or a monotonic counter, and is 236 * only suitable for computing time deltas. The value returned from 237 * this function is a u4 and should only be used for debugging 238 * messages. TODO: make this value relative to the start-up time of 239 * the VM. 240 */ 241 INLINE u4 dvmGetRelativeTimeMsec(void) { 242 return (u4)(dvmGetRelativeTimeUsec() / 1000); 243 } 244 245 /* 246 * Get the current per-thread CPU time. This clock increases monotonically 247 * when the thread is running, but not when it's sleeping or blocked on a 248 * synchronization object. 249 * 250 * The absolute value of the clock may not be useful, so this should only 251 * be used for time deltas. 252 * 253 * If the thread CPU clock is not available, this always returns (u8)-1. 254 */ 255 u8 dvmGetThreadCpuTimeNsec(void); 256 257 /* 258 * Per-thread CPU time, in micros. 259 */ 260 INLINE u8 dvmGetThreadCpuTimeUsec(void) { 261 return dvmGetThreadCpuTimeNsec() / 1000; 262 } 263 264 /* 265 * Like dvmGetThreadCpuTimeNsec, but for a different thread. 266 */ 267 u8 dvmGetOtherThreadCpuTimeNsec(pthread_t thread); 268 INLINE u8 dvmGetOtherThreadCpuTimeUsec(pthread_t thread) { 269 return dvmGetOtherThreadCpuTimeNsec(thread) / 1000; 270 } 271 272 /* 273 * Sleep for increasingly longer periods, until "maxTotalSleep" microseconds 274 * have elapsed. Pass in the start time, which must be a value returned by 275 * dvmGetRelativeTimeUsec(). 276 * 277 * Returns "false" if we were unable to sleep because our time is up. 278 */ 279 bool dvmIterativeSleep(int iteration, int maxTotalSleep, u8 relStartTime); 280 281 /* 282 * Set the "close on exec" flag on a file descriptor. 283 */ 284 bool dvmSetCloseOnExec(int fd); 285 286 /* 287 * Unconditionally abort the entire VM. Try not to use this. 288 * 289 * NOTE: if this is marked ((noreturn)), gcc will merge multiple dvmAbort() 290 * calls in a single function together. This is good, in that it reduces 291 * code size slightly, but also bad, because the native stack trace we 292 * get from the abort may point at the wrong call site. Best to leave 293 * it undecorated. 294 */ 295 void dvmAbort(void); 296 297 #if (!HAVE_STRLCPY) 298 /* Implementation of strlcpy() for platforms that don't already have it. */ 299 size_t strlcpy(char *dst, const char *src, size_t size); 300 #endif 301 302 /* 303 * Allocates a memory region using ashmem and mmap, initialized to 304 * zero. Actual allocation rounded up to page multiple. Returns 305 * NULL on failure. 306 */ 307 void *dvmAllocRegion(size_t size, int prot, const char *name); 308 309 /* 310 * Returns the pointer to the "absolute path" part of the given path 311 * string, treating first (if any) instance of "/./" as a sentinel 312 * indicating the start of the absolute path. If the path isn't absolute 313 * in the usual way (i.e., starts with "/") and doesn't have the sentinel, 314 * then this returns NULL. 315 * 316 * For example: 317 * "/foo/bar/baz" returns "/foo/bar/baz" 318 * "foo/./bar/baz" returns "/bar/baz" 319 * "foo/bar/baz" returns NULL 320 * 321 * The sentinel is used specifically to aid in cross-optimization, where 322 * a host is processing dex files in a build tree, and where we don't want 323 * the build tree's directory structure to be baked into the output (such 324 * as, for example, in the dependency paths of optimized dex files). 325 */ 326 const char* dvmPathToAbsolutePortion(const char* path); 327 328 #endif /*_DALVIK_MISC*/ 329
